U.S. patent application number 15/324782 was filed with the patent office on 2017-07-13 for kit for foot arthroplasty.
The applicant listed for this patent is BIOTECH ORTHO. Invention is credited to Jean-Alain COLOMBIER.
Application Number | 20170196697 15/324782 |
Document ID | / |
Family ID | 51830459 |
Filed Date | 2017-07-13 |
United States Patent
Application |
20170196697 |
Kind Code |
A1 |
COLOMBIER; Jean-Alain |
July 13, 2017 |
KIT FOR FOOT ARTHROPLASTY
Abstract
Disclosed is an assembly for foot arthroplasty, including a
plurality of successively larger implants (10, 20, 30, 40) and a
single drill (60); each implant includes, relative to a central
portion (11), a proximal pin (12, 22, 32, 42) and a distal pin (13,
23, 33, 43) that is shorter than the proximal pin, the pins and the
drill being tapered by 2 to 6.degree..
Inventors: |
COLOMBIER; Jean-Alain;
(BALMA, FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BIOTECH ORTHO |
SALON DE PROVENCE |
|
FR |
|
|
Family ID: |
51830459 |
Appl. No.: |
15/324782 |
Filed: |
July 2, 2015 |
PCT Filed: |
July 2, 2015 |
PCT NO: |
PCT/FR2015/051832 |
371 Date: |
January 9, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B 17/1615 20130101;
A61F 2002/4233 20130101; A61F 2/4225 20130101; A61F 2002/30616
20130101; A61F 2002/4228 20130101; A61B 17/1682 20130101 |
International
Class: |
A61F 2/42 20060101
A61F002/42; A61B 17/16 20060101 A61B017/16 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 10, 2014 |
FR |
1456673 |
Claims
1. A kit for foot arthroplasty comprising a plurality of implants
(10, 20, 30, 40) of increasing sizes and a single bit (60), each
implant comprising, starting from a median portion (11), a proximal
stem (12, 22, 32, 42) and a distal stem (13, 23, 33, 43) shorter
than the proximal stem, these stems and this bit having equal
conical tapers comprised between 2 and 6.degree..
2. A kit according to claim 1, wherein the distal stem of an
implant has the same length as the proximal stem of another
implant.
3. A kit according to claim 1, wherein the stems and the bit have a
conical taper of 4.8.degree. approximately.
4. A kit according to claim 1, wherein the bit comprises on its
working stem at least one visual marker (65A, 65B, 65C, 65D, 65E)
defining, from the point of that bit, a penetration distance equal
to the length of at least one distal or proximal stem of an implant
of said set.
5. A kit according to claim 1, wherein the implants, classified in
increasing order of size, each have (except for the largest) a
proximal stem of which the length is equal to that of the distal
stem of the next implant.
6. A kit according to claim 5, wherein the bit comprises a visual
marker on its working stem for each of the different lengths of the
stems of the implants of said set.
7. A kit according to claim 6, wherein with each of the different
lengths of stem there is associated a specific texture present on
the stems having that length and between the visual marker
associated with that length and the preceding marker.
8. A kit according to claim 1, wherein the median parts are
ball-shaped.
9. A kit according to claim 8, wherein the median parts have
transverse dimensions which increase on going from a given implant
to an implant of larger size.
10. A kit according to claim 2, wherein the stems and the bit have
a conical taper of 4.8.degree. approximately.
11. A kit according to claim 2, wherein the bit comprises on its
working stem at least one visual marker (65A, 65B, 65C, 65D, 65E)
defining, from the point of that bit, a penetration distance equal
to the length of at least one distal or proximal stem of an implant
of said set.
12. A kit according to claim 3, wherein the bit comprises on its
working stem at least one visual marker (65A, 65B, 65C, 65D, 65E)
defining, from the point of that bit, a penetration distance equal
to the length of at least one distal or proximal stem of an implant
of said set.
13. A kit according to claim 2, wherein the implants, classified in
increasing order of size, each have (except for the largest) a
proximal stem of which the length is equal to that of the distal
stem of the next implant.
14. A kit according to claim 3, wherein the implants, classified in
increasing order of size, each have (except for the largest) a
proximal stem of which the length is equal to that of the distal
stem of the next implant.
15. A kit according to claim 2, wherein the median parts are
ball-shaped.
16. A kit according to claim 3, wherein the median parts are
ball-shaped.
17. A kit according to claim 4, wherein the median parts are
ball-shaped.
18. A kit according to claim 5, wherein the median parts are
ball-shaped.
19. A kit according to claim 6, wherein the median parts are
ball-shaped.
20. A kit according to claim 7, wherein the median parts are
ball-shaped.
Description
[0001] The invention concerns a set of implants for performing foot
arthroplasty, that is to say to surgically reform a joint of the
foot, whether it be interphalangeal or metatarsophalangeal.
[0002] Various techniques are known for reforming a joint. Thus
document WO-2010/079288 discloses an orthopaedic implant used in
arthroplasty of the finger comprising a first member provided to be
implanted in a proximal phalanx and a second member provided to be
implanted in an adjacent distal phalanx, each member comprising a
stem for implantation in the bone and an interphalangeal joint
head, the head of the first member having a biconvex joint surface
with a central valley and the head of the second member having a
biconcave joint surface arranged to cooperate with said biconvex
surface and comprising a central crest.
[0003] In the case of foot arthroplasty, it is known to use a
member formed from two stems extending in opposite directions from
each other from a median ball-shaped part. The stems are of
different lengths, the stem that is provided to be implanted in a
phalanx referred to as distal--referred to as distal stem--being
shorter than the stem provided to be implanted in a phalanx
referred to as proximal--referred to as proximal phalanx (it is to
be recalled that the distal phalanx is further from the ankle than
the proximal phalanx and is thus shorter than it). The material
constituting such a one-piece implant is chosen so as to have
compatible flexibility with that sought for the joint to
reconstitute (silicone in practice).
[0004] When such an implant is implanted, the surgeon begins by
incising the tendon actuating the movement of the distal phalanx
relative to the proximal phalanx and a bit is used to bore a canal
in one then the other of the phalanxes before inserting the
corresponding stem therein.
[0005] In practice a choice must be made between several sizes of
implants according to the configuration of the joint to be
reformed; it can indeed be understood that the larger the joint to
reconstitute, the larger must be the size of the implant; there are
currently between 2 and 5 different sizes within a set of implants.
By way of example, if two implants of successive size are
considered, it is possible to have stems of the same diameters and
the same lengths, but median parts of different diameters, or on
the contrary median parts of the same diameters separating stems of
different diameters and lengths. According to the diameter of the
implant chosen, the surgeon chooses a bit of appropriate diameter
and bores a canal of length hardly greater than that of the
corresponding stem.
[0006] Thus, a set of implants conventionally comprises a plurality
of implants as well as a plurality of bits; furthermore, as the
implants are usually obtained by molding, as many different molds
are required as there are implants in the set considered.
[0007] The invention is directed to simplifying the constitution of
a set of such implants for foot arthroplasty, or even its its
manufacture.
[0008] To that end it provides a set of implants for foot
arthroplasty comprising a plurality of implants of increasing sizes
and a single bit, each implant comprising, starting from a median
portion, a proximal stem and a distal stem shorter than the
proximal stem, these stems and this bit having equal conical tapers
comprised between 2 and 6.degree.; preferably, the stems and the
bit have a conical taper of 4.8.degree. approximately.
[0009] Preferably, the distal stem of an implant has the same
length as the proximal stem of another implant, which simplifies
the formation of the molds for manufacture of the implants of a
same set.
[0010] Advantageously, the bit comprises on its working stem at
least one visual marker defining, from the point of that bit, a
penetration distance equal to the length of at least one distal or
proximal stem of an implant of said set. This enables the surgeon
to make a good estimate of the depth to which he must bore a canal
which is to receive a given stem of a chosen implant.
[0011] Preferably, the implants, classified in increasing order of
size, each have (except for the largest) a proximal stem of which
the length is equal to that of the distal stem of the next
implant.
[0012] Advantageously, the bit comprises a visual marker on its
working stem for each of the different lengths of the stems of the
implants of said set. However, a number of markers equal to N+1
suffices if N is the number of implants.
[0013] Advantageously, with each of the different lengths of stem
there is associated a specific texture present on the stems having
that length and between the visual marker associated with that
length and the preceding marker. This facilitates the perception by
the surgeon of the marker to use when boring a canal which is to
receive a given stem of a chosen implant.
[0014] Preferably, the median parts are ball-shaped, spherical,
oval or ellipsoidal, with diameters (or transverse dimensions)
which advantageously increase on going from a given implant to an
implant of larger size.
[0015] Objects, features and advantages of the invention appear
from the following description, given by way of illustrative
non-limiting example, with reference to the accompanying drawing in
which:
[0016] FIG. 1 is a side view of an implant forming part of a set in
accordance with the invention,
[0017] FIG. 2 is a side view of an implant forming part of a set in
accordance with the invention, and
[0018] FIG. 3 is a side view of a set of four implants and of the
associated bit.
[0019] FIG. 1 represents an implant 10 comprising a median part 11
formed from a ball of a given diameter D and two stems 12 and 13
extending away from each other from that median part. These two
stems are of different lengths, the stem 12, referred to as
proximal stem (provided to be implanted in a proximal phalanx)
being longer than implant 13, referred to as distal stem (provided
to be implanted in a distal phalanx). The ratio between the length
"I" of the distal stem and the length of the proximal stem "L" is
for example comprised between 1/2 and 4/5. These lengths are
measured between the end 12A or 13A (in practice rounded) of the
stems and the median part 11 here likened to a real sphere (the
fictional contour of this sphere is represented in dashed line in
FIG. 1).
[0020] The stems are joined to the median part by transition zones
14 and 15;
[0021] According to the invention, each of the stems has a conical
shape with the same conical taper; this conical taper is in
practice chosen between 2 and 6.degree., for example 4.8.degree., a
value which enables the drilling to be facilitated by the conical
taper, without however involving a high increase in the entry
diameter of the canal so formed.
[0022] Such an implant is in practice formed from a biocompatible
material, for example medical silicone.
[0023] The bit, designated by the reference 60, comprises, beyond a
holding portion 61, a working stem 62 comprising longitudinal
grooves 63 (with possibly a helical component) bordering cutting
ridges 64; this working stem has the same conical taper as the
stems of the implant 10. On this working stem markers 65A and 65B
are advantageously visible, which are situated relative to the
point of the working stem at distances to which the bit must
penetrate into the bone to enable proper location of a stem in the
bone of the phalanx which is to receive it (marker 65A here
corresponds to a depth of penetration useful for the implantation
of the distal stem and marker 65B corresponds to the depth of
penetration useful for the implantation of the proximal stem. Of
course, it is possible for these markers not to be present, the
surgeon being able to define by himself the depth of boring from
the dimensions of the implant to be fitted.
[0024] FIG. 3 represents an example of a set of implants comprising
implants in accordance with that of FIG. 1 and a single bit in
accordance with FIG. 2. The various implants have stems having a
same conical taper, equal to that of the bit. The number of
implants within a set is here arbitrarily chosen to be four.
[0025] According to a preferred particular feature of the implants
of the set, the proximal stem of the smallest implant has the same
length as the distal stem of the implant of immediately greater
size. In other words, if the four implants represented in FIG. 3
are denoted 10, 20, 30 and 40, the proximal stem 12 of the implant
10 has the same length as the distal stem 23 of the implant 20, the
proximal stem 22 of that implant 20 has the same length as the
distal stem 33 of the implant 30, and the proximal stem 32 of that
implant 30 has the same length as the distal stem 43 of the implant
40.
[0026] In FIG. 1, which is directed to showing the general geometry
of the implants of a set in accordance with the invention, an
arbitrary choice has been made whereby that the implant 10 of FIG.
3 is indicated rather than, for example, the implant 40.
[0027] It can be understood that an advantage of such a graduation
of the implant stems is that, in particular, the molds for molding
a given implant adopts, for at least one of its stems, the geometry
of a part of the mold associated with an implant of immediately
greater or smaller size; this results in a simplification in the
manufacture of the molds.
[0028] Another advantage of this graduation is that the bit can
comprise a limited number of visual markers to assist the surgeon
in identifying the level of penetration to which the bit is to be
advanced; the first marker 65A corresponds to the depth of
penetration of the bit to bore the canal which is to receive the
distal stem of the smallest implant, i.e. the implant 10; however
the second marker 65B corresponds to the depth of penetration of
the bit to bore the canal which is to receive the proximal stem of
that implant 10, but also the canal which is to receive the distal
stem of the implant of immediately greater size, i.e. the implant
20; similarly, the marker 65C corresponds to the depth of
penetration associated with the proximal stem of the implant 20 as
well as of the distal stem of the implant 30, and the marker 65D
corresponds to the depth of penetration for the proximal stem of
the implant 30 and of the distal stem of the implant 40.
Furthermore, the marker 65E corresponds to the depth of penetration
of the canal which is to receive the proximal part of the largest
implant.
[0029] It can thus be understood that there is a number of markers
only just equal to N+1 if N is the number of implants.
[0030] To further facilitate the ergonomics of the kit, each stem
can advantageously have a specific texture (this may be a color),
reproduced on the bit. In such a case, advantageously, the texture
of the distal stem 13 of the smallest implant 10 may be reproduced
on the bit between its end and the first marker 65A, the texture in
common to the proximal stem 12 of the first implant and to the
distal stem 23 of the implant 20 may be reproduced between the
first and second markers 65A and 65B, the texture in common to the
proximal stem 22 of the second implant 20 and to the distal stem 33
of the third implant 30 may be reproduced between the markers 65B
and 65B, the texture in common to the proximal stem 32 of the third
implant and to the distal stem 43 of the fourth implant 40 may be
reproduced between the markers 65C and 65D and the texture of the
proximal stem 42 of this last implant may be reproduced between the
markers 65D and 65E. If the surgeon wishes to implant one of the
stems of one of the implants in a phalanx, he can thus know that he
must extend the penetration of the bit until the portion of the bit
having the texture of the stem in question disappears.
[0031] Such a succession of textures is, arbitrarily, shown in FIG.
3 (on the bit alone and not on the implants) by a succession of
light and black zones; as a variant these textures can all be
different. It can however be understood that, in a simplified
version, it may be chosen not to seek to master the surface state
and/or color of the stems of the various implants.
[0032] Advantageously, the lengths of the stems have approximately
equal differences; thus by way of example, the lengths have a
difference of the order of 4 to 6 mm, for example 5 mm (with for
example a succession of lengths of the type 6, 11, 15, 20, 25
mm).
[0033] As regards the median parts, they preferably present a
progression, chosen to be compatible with the variations in
diameter of the stems with regard to these median parts (by way of
example, the diameters will staggered as follows: 5-5.5-8.5-11
mm).
[0034] In practice, prior to actually implanting an implant, a
surgeon makes tests using implants which are dummies (in the sense
that they are representative of the real implants without being
them), so as to ensure that the tests do not risk degrading the
implant which will finally be implanted; these trial implants,
sometimes called ghost implants, have the same progression of
length (as regards the stems) or diameter (as regards the median
parts).
[0035] In the simplified version of a set in accordance with the
invention, it is possible for there to be identity between the
length of a proximal stem of one implant and that of the distal
stem of another implant for only some of the implants, in
particular when the depth of penetration of the bit merits being
viewed only for some of the implants.
[0036] Furthermore, it is possible for this identity of length not
to correspond to implants following in the succession of the
implants by size; thus, it is possible to provide for the proximal
stem of the smallest implant to have the same length as the distal
stem of not the second implant, but of the third, for the proximal
stem of the second implant to have the same length as the distal
stem of the fourth implant, and so forth, which can have the
advantage of obtaining greater flexibility in the choice of the
implant to implant.
[0037] It is to be noted that the invention, with one of the stems
and bit of conical form (with a cross-section which is circular
with a diameter that varies continuously, and linearly in practice)
to be advantageously combined, if desired, with a one-piece
character of each stem; such a one-piece character is not
incompatible with the fact that these stems may, where appropriate,
present a certain degree of flexibility.
* * * * *